Floating sleeves for die bushings



Dec. 25, 1962 R. F. MOYER FLOATING SLEEVES FOR DIE BUSHINGS Filed Dec.25, 1960 ullllllulllluullluu' INVEN TOR. ROBE/P7 FRA/v/ru/v MOVE}? ATTORNE Y inited States Patent Office 3,070,404 Patented Dec. 25, 19623,070,404 FLOATING SLEEVES FOR DIE BUSHINGS Robert Franklin Moyer, 21King Philip Circle, Warwick, R.I. Filed Dec. 23, 1960, Ser. No. 78,043 6Claims. (Cl. 308-4) This invention relates to floating sleeves for diebushings and more particularly to providing a bushing with a pluralityof cylindrical sleeves wherein the aggregate length of the sleeves isless than the length of the bushing so that when the post of a die setenters the bushing it will engage the floating sleeves and therebyprevent the binding of the post with the bushing.

An object of the present invention is to provide a die bushing with aplurality of longitudinally positioned sleeves wherein the aggregatelength of the sleeves is less than the length of the bushing so that thedie post, in the downward stroke of the punch carrying plate whichcauses the post to Injsalign, will engage a floating sleeve with apressure point which rides out or" binding position.

Another object of the present invention is to provide a die bus-hingwith easily replaceable and inexpensive sleeves whereby the bushing lifeis increased while maintaining the needed tolerance accuracy betweenpost and bushing.

In the conventional die set the upper or punch carrying plate isprovided with either two or four bushings located in the corners of theplate. The lower or die carrying plate is provided with either two orfour posts located in the corners of the plate in cooperativerelationship with the respective bushings.

The accuracy of the mating relationship between the post and cooperatingbushing determines the accuracy available between the punch and die andtherefore of the article produced by the punch and die.

As the bushings wear a sloppy relationship developes between the postand mating bushing. Thus, accurately and uniformly sized articles are nolonger produced by the die set. In addition misalignment of the punchwith the die causes breakage to the punch and damage to the die. Punchand die sets, depending upon the size and shape of article produced, maybe extremely costly to produce.

In the normal operation of a die set, the punch and punch carrying orupper plate are subjected to torsion or wrenching due to the exertion ofthe lateralforce created when the punch engages the strip material fromwhich the desired article is produced.

This torsion takes the form of mis-axial-alignment of the post with thebushing. The post is therefore cant ercd as it enters the bushing. Thepoints at which the post engages the bushing are termed pressure points.It is at these pressure points that undue wear is created on thebushing. Thus the life of the bushing is shortened. The die is withheldfrom production. Expensive punches and dies are damaged or destroyedbefore the undue wear is discovered. The accuracy of the articleproduced is destroyed before the useful life of the punch and die isrealized. This undue wear is costly to manufacturers and is an economicwaste.

The present invention was created to overcome undue wear and to increasethe economic life of both the die set and the punch and die. The mannerin which this result is accomplished will presently appear.

Other objects of the present invention will be pointed out in part andbecome apparent in part in the following specification and claims.

Referring to the drawings in which similar characters of referenceindicate corresponding parts in all the figures:

FIGURE 1 is a side elevational view of a die set incorporating thepresent invention.

FIGURE 2 is a horizontal view partly in cross section taken on line 2-2of FIGURE 1.

FIGURE 3 is a vertical cross sectional view through the new and improvedfloating sleeves and die bushing, illustrating the post at the moment ofentry of the punch into the material, whereby pressure points arecreated.

FIGURE 4 is a side elevational view of the new and improved die bushingprovided with floating sleeves.

FIGURE 5 is a top plan view of FIGURE 4.

FIGURE 6 is a bottom plan view of FIGURE 4.

FIGURE 7 is a vertical cross sectional view taken on line 7-7 of FIGURE4.

Reference is now made to FIGURE 1 wherein the conventional die set isillustrated as consisting of a punch carrying plate 11 provided withremovable bushings, generally indicated by reference numeral 12, a stem13, adapted to be held in a punch press, and a punch 14.

The lower or die carrying plate 15 is normally secured to the bed of apunch press (not shown). Plate 15 is provided with posts 16 equal innumber and matingly engaging bushin-gs 12. The die 17 is fixed to plate15 in cooperative relationship with punch 14. A strip of material whichcould be brass, steel or any other material is indicated at 1-8 inposition on die 17 awaiting the reception of punch 14.

The removable bushing 12 consists of a cylindrical housing 20 providedexternally with a small diameter 19 terminating in a shoulder 21, and agroove 22. Internally, housing 20 is provided with an axial bore 23.Bushing 12 is fabricated from tool steel and is hardened and ground toprecise dimensions. This is especially true of axial bore 23 and smalldiameter 19.

A floating or slidably mounted sleeve or liner is provided which iscircumferentially divided into a plurality of sections illustrated asthree in number 30, .31, 32 and pro por-tioned to provide for a spaceequal to the width of one of said bushings in the distance between theends of said axial bore 23. Said sleeves or liners by detachingretaining means on opposite ends of said cylindrical housing are freelyremovable and replaceable in an endwise direction in said axial bore 23.

Sleeves or liners 30, 31, 32 are identical in construction. Therefore,only one will be described in detail.

.The outside diameter 34 of line 30 is five ten thousandths of an inchsmaller than the diameter of axial bore 23 to provide a slipfit orgravitational sliding fit between sleeve 30 and axial bore 23. Theinside diameter 35 of sleeve or liner 30 is between three and five tenthousandths of an inch larger than the standard diameter of a post 16. Apost 16 provided with a standard one inch diameter is manufactured witha tolerance from minus zero to plus two ten thousandths of an inchlarger than the standard diameter. In this way the clearance between theoutside diameter of post 16 and the inside diameter 32 of the sleeve isnever less than one ten thousandth of an inch an never greater than fiveten thou sandths of an inch.

This example of dimensions is cited to illustrate the precision existingbetween the cooperating elements of post 16, sleeve 30 and bushing 12. Avery high degree of manufacturing accuracy is necessary to the properfunction of these cooperating elements.

The length of axial bore 23, dimension A, FIGURE 7, is divided into amultiple number of smaller dimensions, illustrated as four in number.The number four becomes evident when sleeves 30, 31, 32 are counted andthe space B is considered equal to the length of one of the sleeves 30,31, 32. It thus becomes evident that sleeves or liners 30, 31, 32 areslidably mounted in axial bore 23. Through the force of gravity sleeves30, 31, 32 will gravitate to one end as illustrated in FIGURE 7.

To prevent sleeves or liners 30, 31, 32 from sliding beyond the ends ofaxial bore 23, two collars 37, 38 are provided on opposite ends ofcylindrical housing 20. Screws 40 secure collar 38 to housing 20. Screws41 secure collar 37 to the opposite end of housing 20. The insidediameters 42 of collar 38 and 43 of collar 37 are slightly larger insize over the size or dimensions of the inside diameters of sleeves 30,31, 32. Said inside diameters 42, 43 are smaller in diameter than thediameter of axial bore 23. Collars 37, 38 retain sleeves 30, 31, 32between them.

In operation, as punch 14 engages strip material 18 held in die 17,punch 14 and punch carrying plate .11 and therefore bushings 12 aresubject to torsion and wrenching and therefore misalignment from aparallel relationship with lower plate 15 and posts 16. Thismisalignment, illustrated in FIGURE 3, creates pressure points 50 and51.

Prior to the present invention these pressure points would be providedbetween post 16 and axial bore 23 with the consequent wear on bore 23.With the advent of sleeves 30, 31, 32 the sleeves slide along axial bore23 and thereby realign posts 16 with bushings 12 by sliding the linersor sleeves 30, 31, 32 along axial bore 23. The thrust of post 16 againstsleeves 30, 31, 32 is greatly minimized due to the sliding movement ofthe sleeves 30, 31, 32.

Thus the axial bore 23 is provided with an extended life; the sleeves orliners 30, 31, 32 are easily replaced and inexpensive to manufacture;and the necessary accurate relation between the posts and bushings ismaintained. When a sleeve 36, 31, 32 wears, it is more readily apparent;thereby, preventing a clash of punch 14 with die 17 which results incostly damage to the punch 14 and/or die 17.

Having shown and described a preferred embodiment of the presentinvention by way of example, it should be realized that structuralchanges could be made and other examples given without departing fromeither the spirit or scope of this invention.

What I claim is:

1. In a die set having in combination a punch carrying plate providedwith a plurality of removable bushings and a cooperating die carryingplate provided with a plurality of mating posts for aligning the diecarrying plate with the punch carrying plate, that improvement in saidbushings which consists of a bushing comprising a cylindrical housinghaving externally a small diameter terminating in a shoulder, andprovided internally with an axial bore, said small diameter removablysecured in said punch carrying plate with said shoulder abutting theunderside of said punch carrying plate, a liner slidably mounted in saidaxial bore and circumferentially divided into a plurality of sections,proportioned to provide a space equal to the width of one of saidsections in the distance between the ends of said axial bore, a firstcollar having an inside diameter smaller in diameter than the diameterof said axial bore, a second collar having an inside diameter smaller indiameter than the diameter of said axial bore and means to secure saidfirst collar and said second collar to opposite ends of said cylindricalhousing to removably secure said plurality of sections, slidablymounted, in said axial bore, whereby the mating post moves said sectionsin one direction and gravity returns said sections to initial position.

2. In a die set having in combination a punch carrying plate providedwith a plurality of removable bushings and a cooperating die carryingplate provided with a plurality of mating posts for aligning the diecarrying plate with the punch carrying plate, that improvement in saidbushings which consists of a bushing comprising an axial bore, a linerslidably mounted in said axial bore and circumferentially divided into aplurality of sections proportioned to provide for longitudinal movementof said sections in said axial bore, collar means secured to oppositeends of said bushing to retain said sections in said axial bore and topermit misalignment of a post with a mating bushing whereby matingmovement of said bushing with a post causes said sections to engage saidpost and through longitudinal sliding movement of said sections in saidaxial bore to realign said post with its mating bushing.

3. In a die set having in combination a punch carrying plate providedwith a plurality of removably secured bushings and a cooperating diecarrying plate provided with a plurality of mating posts for aligningthe die carrying plate with the punch carrying plate, that improvementin said bushings which consists of a bushing comprising an axial bore, aliner slidably mounted in said axial bore and circumferentially dividedinto a plurality of sections proportioned to provide for longitudinalmovement of said sections, a distance equal to the width of one of saidsections, in said axial bore, collar means removably secured to oppositeends of said bushing whereby said sections are freely removable andreplaceable in a longitudinal direction along said axial bore, thedifference between the diameter of said axial bore and the outsidediameter of said liner being five ten thousandths of an inch to providea slip fit between the outside diameter of said liner and said axialbore, longitudinal sliding movement of said liners in said axial boresrealigning the die carrying plate with the punch carrying plate throughthe mating posts.

4. In a die set having in combination a punch carrying plate providedwith a plurality of removably secured bushings and a cooperating diecarrying plate provided with a plurality of mating posts for aligningthe die carrying plate with the punch carrying plate, that improvementin said bushings which consists of a bushing comprising an axial bore, aliner sldably mounted in said axial bore and circumferentially dividedinto a plurality of sections proportioned to equal a length less thanthe full length of said axial bore, to provide for longitudinal slidingmovement of said sections in said axial bore, collar means removablysecured to opposite ends of said bushing, said collar means freelyslidable over a mating post, whereby said sections are retained in saidaxial bore and are removable and replaceable in said axial bore, saidliner having an inside diameter, the difference in diameters between themating post and the inside diameter of the cooperating linerapproximating the difference between one ten thousandth of an inch andfive ten thousandths of an inch, whereby misalignment of the mating postwith the cooperating liner causes said post to engage said sections toslide said sections in said axial bore to realign said mating post withthe cooperating liner and bushing and thereby align said punch carryingplate with said die carrying plate.

5. In a die set having in combination a punch carrying plate providedwith a plurality of removably secured bushings and a cooperating diecarrying plate provided with a plurality of mating posts for aligningthe die carrying plate with the punch carrying plate, that improvementin said bushings which consists of a bushing comprising an axial bore, aliner slidably mounted in said axial bore and circumferentially dividedinto a plurality of sections proportioned to equal a length less thanthe full length of said axial bore, to provide for longitudinal slidingmovement of said sections in said axial bore, collar means removablysecured to opposite ends of said bushing, said collar means freelyslidable over a mating post, whereby said sections are retained in saidaxial bore and are removable and replaceable in said axial bore, saidsections having an inside diameter, whereby misalignment of the matingpost with the cooperating liner causes said post to engage the insidediameter of said sections to slide said sections in said axial bore torealign said mating post with the cooperating liner and bushing andthereby align said punch carrying plate with said die carrying plate.

6. In a die set having in combination a punch carrying plate providedwith a plurality of removable bushings and a cooperating die carryingplate provided with a plurality of mating posts for aligning the diecarrying plate with the punch carrying plate, that improvement in saidbushings which consists of a bushing comprising an axial bore, a linerslidably mounted in said axial bore and circumferentially divided into aplurality of sections proportioned to equal a length less than the fulllength of said axial bore, collar means removably secured to oppositeends of said bushing, said collar means freely slidable over a matingpost, whereby said sections are retained in said axial bore and areremovable and replaceable in said axial bore, the difference between thediameter of said axial bore and the outside diameter of said liner beingapproximately five ten thousandths of an inch to provide a gravitationalsliding fit for said liner in cooperation with said axial bore, saidliner having an inside diameter, the difference in diameter between themating post and the in- 6 side diameter of said liner approximating twoten thousandths of an inch, whereby misalignment of the mating post withthe inside diameter of said liner causes said post to engage the insidediameters of said sections to slide said sections in said axial bore torealign said mating post with said inside diameter and therefore saidbushings and said punch carrying plate with said die carrying plate.

References Cited in the file of this patent UNITED STATES PATENTS2,422,774 Conner June 24, 1947 2,711,103 Miner Jan. 21, 1955 FOREIGNPATENTS 1,041,744 Germany Oct. 23, 1958

